Oxymercuration of ethisterone derivatives is old, see Helv. Chim. Acta. 26, 680 (1943).
The use of mercury salts as catalysts for enhancing the formation of the pregnane side chain on 17.alpha.-ethynyl steroids is well known. See, for example, U.S. Pat. Nos. 4,368,160, 4,102,908, 3,764,615, 3,741,997, and 4,443,377. See also U.S. patent application Ser. No. 501,032, filed 6/03/83.
In addition, the oxymercuration of epi-ethisterone and other 17.beta.-ethynyl steroids is disclosed in U.S. patent application Ser. No. 673,961, filed Nov. 21, 1984.
The reaction of vinyl mercury acetates with zinc powder in glacial acetic acid to replace the mercuric acetate group with a proton is disclosed in "Stereochemistry of the Acetoxymercuration of Alkynes. Synthesis of Vinyl Acetates", J. Org. Chem. 1982, 47, 3707-3712.